Merge tag 'block-5.18-2022-04-29' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:

 - Revert of a patch that caused timestamp issues (Tejun)

 - iocost warning fix (Tejun)

 - bfq warning fix (Jan)

* tag 'block-5.18-2022-04-29' of git://git.kernel.dk/linux-block:
  bfq: Fix warning in bfqq_request_over_limit()
  Revert "block: inherit request start time from bio for BLK_CGROUP"
  iocost: don't reset the inuse weight of under-weighted debtors

Author: torvalds

block/bfq-iosched.c

@@ -569,7 +569,7 @@ static bool bfqq_request_over_limit(struct bfq_queue *bfqq, int limit)
 	struct bfq_entity *entity = &bfqq->entity;
 	struct bfq_entity *inline_entities[BFQ_LIMIT_INLINE_DEPTH];
 	struct bfq_entity **entities = inline_entities;
-	int depth, level;
+	int depth, level, alloc_depth = BFQ_LIMIT_INLINE_DEPTH;
 	int class_idx = bfqq->ioprio_class - 1;
 	struct bfq_sched_data *sched_data;
 	unsigned long wsum;
@@ -578,15 +578,21 @@ static bool bfqq_request_over_limit(struct bfq_queue *bfqq, int limit)
 	if (!entity->on_st_or_in_serv)
 		return false;
 
+retry:
+	spin_lock_irq(&bfqd->lock);
 	/* +1 for bfqq entity, root cgroup not included */
 	depth = bfqg_to_blkg(bfqq_group(bfqq))->blkcg->css.cgroup->level + 1;
-	if (depth > BFQ_LIMIT_INLINE_DEPTH) {
+	if (depth > alloc_depth) {
+		spin_unlock_irq(&bfqd->lock);
+		if (entities != inline_entities)
+			kfree(entities);
 		entities = kmalloc_array(depth, sizeof(*entities), GFP_NOIO);
 		if (!entities)
 			return false;
+		alloc_depth = depth;
+		goto retry;
 	}
 
-	spin_lock_irq(&bfqd->lock);
 	sched_data = entity->sched_data;
 	/* Gather our ancestors as we need to traverse them in reverse order */
 	level = 0;

block/blk-iocost.c

@@ -2322,7 +2322,17 @@ static void ioc_timer_fn(struct timer_list *timer)
 				iocg->hweight_donating = hwa;
 				iocg->hweight_after_donation = new_hwi;
 				list_add(&iocg->surplus_list, &surpluses);
-			} else {
+			} else if (!iocg->abs_vdebt) {
+				/*
+				 * @iocg doesn't have enough to donate. Reset
+				 * its inuse to active.
+				 *
+				 * Don't reset debtors as their inuse's are
+				 * owned by debt handling. This shouldn't affect
+				 * donation calculuation in any meaningful way
+				 * as @iocg doesn't have a meaningful amount of
+				 * share anyway.
+				 */
 				TRACE_IOCG_PATH(inuse_shortage, iocg, &now,
 						iocg->inuse, iocg->active,
 						iocg->hweight_inuse, new_hwi);

block/blk-mq.c

@@ -1131,14 +1131,7 @@ void blk_mq_start_request(struct request *rq)
 	trace_block_rq_issue(rq);
 
 	if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
-		u64 start_time;
-#ifdef CONFIG_BLK_CGROUP
-		if (rq->bio)
-			start_time = bio_issue_time(&rq->bio->bi_issue);
-		else
-#endif
-			start_time = ktime_get_ns();
-		rq->io_start_time_ns = start_time;
+		rq->io_start_time_ns = ktime_get_ns();
 		rq->stats_sectors = blk_rq_sectors(rq);
 		rq->rq_flags |= RQF_STATS;
 		rq_qos_issue(q, rq);